Improvement in machines for cutting files



M. H. FISHER. FILE CUTTING MACHINE.

No. 37,419. Patented Jan. 13, 1863;

Wihwsas; 2

UNITED STATES PATENT OFFIC MAJOR H. FISHER, OF BRIDGEPORT, CONNECTICUT,ASSIGNOR TO THE FRANKLIN FILE COMPANY, OF SAME PLACE.

IMPR'C DVEMENT IN MACHINESFOR CUTTING FILES.

Specification forming part of LcttersPatent N0. 37,4 19, dated January13, 1863.-

' To aZZwFwm it may concern:

improved method of attaching the chisel to the chisel-arm. It isapplicable to the machinery described in said patent, or to any otherfile-cutting machinery now in use, requiring a chisel arm and holderactuated by shafts and cams or other suitable device. Such machinery,being well known, need not be'de'scribed. The accompanying drawingsfully illustrate my invention.

Figure 1 is a top view of my'chisel arm and holder with the chisel inits place. Fig. 2 isv a bottom view of the same. Fig. 3 is a verticallongitudinal section of the same inthe line A B of Fig. 1. Fig. 4 is aview of the back side of the chisel.

The same letters refer o the same parts in the several figures. Thechisel-arm a is constructed of the same material, and is attached to themachine in the same manner as the one patented to me as assignee on the5th of February, 1856, and the only material difference between mypresent invention, and that patented in 1856 consists in the manner inwhich I secure the chisel E inthe oblique slot 65 of the chisel-arm a.Reference may be had to the said patent of 1856, from which the presentimprovement will fully appear. I now dispense entirely with the slidingchisel-holder 9, described in the patent of 1856, and with the coiledspring underneath it, having found from experience that they cannot beused to advantage, and that they do not accomplish the desired object.In ,.place of these I attach a steel point, b, to the under side of thechisel-arm, which point projectsjust fa r enough into the oblique slotof the said arm to fit into the inclined notch i of the chisel when thechisel is placed in its properposition.

The inclined notch 'i on the back part of the chisel, it will beobserved, is another new feature. In the patent of 1856 there was merelya round hole ornotch, in the chisel, into which the point'of the slidingchisel-holder fitted so that the chisel could not rise and fall in theslot of the chisel-arm without carrying the sliding chisel-holder alongwith it, so that if the sliding chisel holder or the spring underneathit became clogged, as frequently happened, the chiselconld not rise orfall independent of the chisel-arm. Between the front side of the chiselE and the end of the chisel-arm a, I .now place a circular spring, 0,which spring is located partly within the chiselarm a, and projects intothe slot of said arm far enough to press against the front side of thechisel. At the end of the chisel-arm a is a set-screw, S, by means ofwhich the pressure of the spring 0 against the front of the chisel maybe increased 'or diminished as desired.

. \Vh'en the filecutting machine is ready for operation, the chisel isinthe position shown in Fig. 1. As the arm a descends the edge of thechisel is brought in contact with the surface of the fileblank, so thatwhen the hammer falls the edge of the chisel is driven downward, and atthe same time alittle backward, owing to the inclination of the inclinednotch i. This slight backward motion of the chisel is of the utmostimportance, as it gives the proper form to the burr, which cannot beproduced in any other'manner. As the chiselarm rises after the stroke ofthe hammer the file-blank is fed forward, and the pressure of the edgeof the chisel against the burr raised by the out last madeis so relievedby the spring 0 that neither the edge of the chisel or of the burr isinjured. It will also be observed that by means of the inclinednotch,and owing to the manner in which the chisel is held in thechisel-arm, that the chisel has an up-anddown motion, abackward-and-forward motion, and a motion from one side to the otherindependent of the chisel arm. Thus, when the face of said blank, andwhen the hammer falls 2. The adjustable spring 0, in combination thechisel is driven downward and backward, withthe notch i, substantiallyas and for the while the chisel-arm itself remains stationary. purposesdescribed.

Having thus described my invention, what I claim therein as new, anddesire to secure by Witnesses:

JAMES L. GOULD, E. B. GOODSELL.

MAJOR H. FISHER.

Letters Patent, is-- I. The inclined notch i in the'chisel.

